A cardiologist in the carotids

The impact of endovascular repair on specialties performing abdominal aortic aneurysm repair

BACKGROUND

Abdominal aortic aneurysm (AAA) repair has been performed by various surgical specialties for many years. Endovascular aneurysm repair (EVAR) may be a disruptive technology, having an impact on which specialties care for patients with AAA. Therefore, we examined the proportion of AAA repairs performed by various specialties over time in the United States and evaluated the impact of the introduction of EVAR.

METHODS

The Nationwide Inpatient Sample (2001-2009) was queried for intact and ruptured AAA and for open repair and EVAR. Specific procedures were used to identify vascular surgeons (VSs), cardiac surgeons (CSs), and general surgeons (GSs) as well as interventional cardiologists and interventional radiologists for states that reported unique treating physician identifiers. Annual procedure volumes were subsequently calculated for each specialty.

RESULTS

We identified 108,587 EVARs and 85,080 open AAA repairs (3011 EVARs and 12,811 open repairs for ruptured AAA). VSs performed an increasing proportion of AAA repairs during the study period (52% in 2001 to 66% in 2009; P < .001). GSs and CSs performed fewer repairs during the same period (25% to 17% [P < .001] and 19% to 13% [P < .001], respectively). EVAR was increasingly used for intact (33% to 78% of annual cases; P < .001) as well as ruptured AAA repair (5% to 28%; P < .001). The proportion of intact open repairs performed by VSs increased from 52% to 65% (P < .001), whereas for EVAR, the proportion went from 60% to 67% (P < .001). The proportion performed by VSs increased for ruptured open repairs from 37% to 53% (P < .001) and for ruptured EVARs from 28% to 73% (P < .001). Compared with treatment by VSs, treatment by a CS (0.55 [0.53-0.56]) and GS (0.66 [0.64-0.68]) was associated with a decreased likelihood of undergoing endovascular rather than open AAA repair.

CONCLUSIONS

VSs are performing an increasing majority of AAA repairs, in large part driven by the increased utilization of EVAR for both intact and ruptured AAA repair. However, GSs and CSs still perform AAA repair. Further studies should examine the implications of these national trends on the outcome of AAA repair.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

Physician specialty and carotid stenting among elderly medicare beneficiaries in the United States

BACKGROUND

The use of carotid stenting is rising across the United States. How physician specialty relates to its utilization rates or outcomes is uncertain.

METHODS

We performed an observational analysis of fee-for-service Medicare beneficiaries 65 years or older undergoing carotid stenting between 2005 and 2007 in 306 hospital referral regions (HRRs). We first determined how frequently carotid stenting was performed by different specialists within each HRR and then used multivariable regression models to compare population-based utilization rates and 30-day outcomes for this procedure across HRRs based on the proportion performed by cardiologists, surgeons, radiologists, or a mix of specialists.

RESULTS

In 272 HRRs where at least 15 procedures were performed during the study period, we identified 28 700 carotid stenting procedures performed by 2588 operators. While cardiologists made up approximately one-third of these operators, they were responsible for 14 919 (52.0%) procedures. Significant differences were noted in the characteristics of patients treated by cardiologists compared with other specialties, including higher rates of invasive cardiac procedures and lower rates of acute stroke or transient ischemic attacks in the 180 days prior to carotid stenting. Population-based utilization rates were significantly higher in HRRs where cardiologists performed most procedures relative to HRRs where most were done by other specialists or a mix of specialists (P < .001). In contrast, risk-standardized outcomes did not differ across HRRs based on physician specialty.

CONCLUSIONS

Carotid stenting is being performed by operators from diverse specialties. Hospital referral regions where cardiologists perform most procedures have higher population-based utilization rates with similar outcomes.

Carotid Artery Stenting: Update

"Extracranial carotid artery stenosis is responsible for approximately 20-30% of ischemic strokes. Traditionally, carotid artery stenosis has been treated with carotid endarterectomy. However, the low periprocedural complication rate and the mid term durability of carotid artery stenting has made it a competitive alternative treatment strategy. This update reviews the technical aspects of carotid artery stenting, clinical data supporting carotid artery stenting-particularly in high risk patients, and the complications associated with carotid artery stenting."

Carotid artery stenting: Impact of practitioner specialty and volume on outcomes and resource utilization

OBJECTIVES

A variety of endovascular specialists perform carotid artery stenting (CAS), but little data exist on outcomes and resource utilization among these specialists. We analyzed differences in outcomes after CAS was performed by radiologists (RAD), cardiologists (CRD), and vascular surgeons (VAS).

METHODS

Secondary data analysis of the 2005-2006 State Inpatient Databases for New Jersey were analyzed. Patients with elective admission to the hospital who had CAS procedure <or=2 days after admission were identified. CAS outcomes were analyzed with respect to practitioner specialty and volume, associated complications, and hospital resource utilization.

RESULTS

We identified 625 CAS cases. CRD performed 378 (60.5%), VAS, 199 (31.8%); and RAD, 48 (7.7%). The overall stroke rate was 2.72% and by specialty was CRD, 3.17%; VAS, 2.01%, and RAD, 2.08% (P = .6880). The overall cardiac complication rate was 2.40% (CRD, 2.12%; VAS, 3.02%; RAD, 2.08%; P = .7899). Renal and pulmonary complications were low (0.64% and 0.32%, respectively). Mean hospital length of stay (LOS) in days was significantly shorter for VAS (1.64 +/- 1.40) compared with RAD (2.83 +/- 5.15; P = .0167) and had the same trend compared with CRD (2.14 +/- 3.37; P = .0649). Intensive care unit (ICU) LOS was shorter for VAS (0.52 +/- 0.97) and CRD (0.30 +/- 0.71) than for RAD (2.12 +/- 4.48; P < .0001). The mean total hospital cost was significantly greater for RAD ($20,987 +/- $26,603) and CRD ($18,182 +/- $16,364) than for VAS ($10,000 +/- $4947; P = .0011 and P < .0001, respectively). ICU cost for RAD ($5963 +/- $14,551) was also more than for VAS ($864 +/- $1514; P < .0001) and CRD ($473 +/- $1561; P < .0001). Medical supply costs were significantly greater for CRD ($8772 +/- $9546) than for VAS ($3354 +/- $2261; P < .0001) and RAD ($4964 +/- $2595; P = .0142). Total hospital cost, LOS, and medical supplies were significantly lower for high-volume practitioners vs low-volume practitioners (P < .0001).

CONCLUSION

Stroke rates after CAS did not vary significantly among practitioner specialties. Hospital resource utilization did vary significantly: Vascular surgeons had the lowest utilization of hospital resources for performing CAS. High practitioner volume was associated with lower hospital resource utilization. Elucidation of factors creating resource utilization disparities among endovascular practitioners may lead to improved patient outcomes and permit significant future cost savings for carotid interventions.

Do device characteristics impact outcome in carotid artery stenting?

OBJECTIVES

The study was conducted to identify patient and procedural parameters that negatively impact the 30-day rates for stroke, death and transient ischemic attack (TIA) after carotid artery stenting (CAS) and that might be modified or further studied in future efforts to improve CAS.

METHODS

This was a retrospective investigation of a dual-center CAS database of 701 consecutive CAS patients (414 men; mean age, 72.4 +/- 8.4). A subset of patient-related, lesion-related, or procedure-related variables (age >or=80, left sided lesion, symptomatic, nicotine abuse, hypertension, diabetes mellitus, other peripheral vascular disease, hypercholesterolemia, embolic protection devices usage, predilation, ulcerated lesion, echolucent plaque, restenosis after surgery) were analyzed for association with occurrence of stroke, death, or TIA <or=30 days after CAS. The odds ratio (OR) and 95% confidence interval (CI) and P value were calculated for each variable to predict adverse outcome.

RESULTS

The overall combined rate of stroke, death, and TIA within this database was 3.7% at 30 days. In the total population of 701 patients, only the OR of 2.7 for hypercholesterolemia (95% CI, 1.0 to 7.3; P = .041) was found to be significant. Subgroup analysis of the 304 symptomatic patients (43%) showed that open-cell stent designs and concentric EPD designs yielded an OR of 4.1 (95% CI, 1.4 to 12, P = .0136) and 3.3 (95% CI, 1.016 to 10, P = .0525), respectively, for 30-day stroke/death/TIA within this database. Analysis of open-cell stent designs and concentric EPD designs in patients with echolucent lesions yielded an OR of 3.1 (95% CI,1.2 to 8.2, P = .0343) and 3.7 (95% CI, 1.3 to 10, P = .0174), respectively, for 30-day stroke/death/TIA.

CONCLUSIONS

We conclude that increased analysis of device design variables may be necessary. Particularly in symptomatic patients or with echolucent lesions, closed-cell design and eccentric filters seem superior. Prospective investigation comparing open-cell vs closed-cell stents and eccentric vs concentric filter devices may be warranted.

Patient selection for carotid stenting versus endarterectomy: A systematic review

Carotid artery stenting has emerged as an alternative to carotid endarterectomy for the treatment of severe extracranial carotid stenosis in patients with anatomic or clinical factors that increase their risk of complications with surgery, yet there remains a substantial amount of variability and uncertainty in clinical practice in the referral of patients for stenting vs endarterectomy. By undertaking a thorough review of the literature, we sought to better define which subsets of patients with "high-risk" features would be likely to preferentially benefit from carotid stenting or carotid endarterectomy. Although only a single randomized trial comparing the outcomes of carotid stenting with distal protection and endarterectomy has been completed, a wealth of observational data was reviewed. Relative to endarterectomy, the results of carotid stenting seem favorable in the setting of several anatomic conditions that render surgery technically difficult, such as restenosis after prior endarterectomy, prior radical neck surgery, and previous radiation therapy involving the neck. The results of stenting are also favorable among patients with severe concomitant cardiac disease. Carotid endarterectomy, alternatively, seems to represent the procedure of choice among patients 80 years of age or older in the absence of other high-risk features. Overall, existing data support the concept that carotid stenting and endarterectomy represent complementary rather than competing modes of therapy. Pending the availability of randomized trial data to help guide procedural selection, which is likely many years away, an objective understanding of existing data is valuable to help select the optimal mode of revascularization therapy for patients with severe carotid artery disease who are at heightened surgical risk.

Long-Term Histopathologic and IVUS Evaluations of a Novel Coiled Sheet Stent in Porcine Carotid Arteries

Carotid angioplasty with stent placement has been proposed as an alternative method for revascularization of carotid artery stenosis. A novel stent with a laser-cut, rolled sheet of Nitinol (EndoTex Interventional Systems, Inc., Cupertino, CA) has been developed to customize treatment of stenotic lesions in carotid arteries utilizing a single stent, designed to adapt to multiple diameters and to tapered or nontapered configurations. The purpose of this study is to evaluate the conformability and vascular response to a novel stent in a chronic porcine carotid model using serial three-dimensional intravascular ultrasound (IVUS) analysis as well as histological examination. Ten Yucatan pigs underwent stent implantation in both normal carotid arteries with adjunctive balloon angioplasty. Three-dimensional IVUS analysis was performed before stent implantation, after adjunctive balloon angioplasty, and at follow-up [1 month (n = 6), 3 months (n = 6), or 6 months (n = 8)]. Histological examination (injury score, percent plaque obstruction, and qualitative analysis) was also performed. All stents were successfully deployed and well apposed in different sized vessels (lumen area range: 19-30 mm(2)). Volumetric IVUS analysis showed no significant difference between the lumen areas before stent implantation and after adjunctive balloon angioplasty and no stent area change at each follow-up point compared to immediately postprocedure. Histological examination revealed minimal injury and neointimal hyperplasia at each follow-up point. In the chronic porcine carotid model, the novel stent system demonstrated good conformability, resulting in minimal vessel injury and neointimal formation.

Cognitive functions in patients with cerebrovascular disease: potential impact of revascularization

The purpose of this review is to assess the impact of luminal restoring of carotid artery stenosis on cognitive functions. Therefore, papers dealing with the neuropsychological influence of carotid artery stenosis and studies comparing the neuropsychological course after respective recanalization have been included.

New technologies meeting old professional boundaries: the emergence of carotid artery stenting

BACKGROUND

Carotid artery stenosis is common and costly. Opinions differ in regard to the impact that carotid angioplasty and stenting (CAS) will have. Vascular surgeons, cardiologists, interventional radiologists, and neurologists all have a stake in the uptake of CAS. We sought to explore physicians' views about the safety and efficacy of CAS and the negotiation of professional boundaries in the treatment of carotid stenosis.

STUDY DESIGN

We performed a qualitative analysis of key informant interviews with 15 physicians, including four internationally renowned key opinion leaders, representing five medical centers with differing experience adopting CAS.

RESULTS

Variation in beliefs about the safety and efficacy of CAS within specialties was overshadowed by variation across the specialties examined. Most informants emphasized the strengths of their specialty in adopting CAS, including frequent patient care (vascular surgery, cardiology, and neurology), extensive catheter experience (cardiology, interventional radiology), and intimate knowledge of the anatomy of vascular and neurovascular disease (vascular surgery, neurology). Several themes were mentioned in regard to the diffusion of CAS, including risks of premature diffusion into low risk populations and the role of patient preferences in CAS uptake. The most common theme in regard to local management of CAS was the strength of interdisciplinary collaboration in the management of patients with carotid artery stenosis.

CONCLUSIONS

CAS challenges physicians from several specialties to safely and effectively manage the uptake of an emerging technology crossing traditional specialty lines. Local collaboration of individual physicians and the departments and professional organizations they comprise, will have an important impact on how this technology is adopted.

Stroke prevention in diabetic and other high cardiovascular risk patients

Diabetes is a major risk factor for stroke that is usually associated with risk factors such as hypertension, obesity, albuminuria, and dyslipidemia. Furthermore, atrial fibrillation and heart failure, two of the most important risk factors of stroke, are common in the diabetic population. With the rising epidemic of diabetes, the incidence of stroke is also on the rise. Implementations of effective stroke prevention strategies appear to be the most rational option to curb this growing epidemic. In this review, we examine the epidemiologic and the pathophysiologic association between stroke and diabetes, highlighting the population-based stroke preventive measures. These include hygienic and lifestyle changes, that if applied effectively could offer a great potential for stroke prevention and reduction of the cardiovascular burden in the diabetic populations.

Staged carotid artery stenting and coronary artery bypass graft surgery: Initial results from a single center

The objective of this study was to assess the clinical course of patients undergoing planned percutaneous carotid stenting followed by staged coronary artery bypass grafting (CABG). Coexisting carotid and coronary atherosclerotic disease is relatively common. A combined or staged surgical approach has a composite stroke, myocardial infarction, or death rate of > 10%. We performed a retrospective search of our single-institution database to identify all patients scheduled to undergo staged carotid stenting followed by CABG. Twenty-three such patients (17 males, 6 females) were identified, with 3/23 (13%) requiring bilateral carotid stenting. Most carotid lesions were asymptomatic (18/26; 69.2%) and severe (mean stenosis, 82.9% 6+/- 8.6%). Stents were successfully placed in 26/26 carotid arteries (100%). One stent procedure (1/26; 3.8%) resulted in a minor stroke, but full recovery occurred within 1 week. There were no other peri-stenting complications. Three patents (3/23; 13%), none of whom suffered an adverse event at carotid stenting, elected not to undergo CABG. The mean interval from last carotid stent to CABG was 69.6 6 +/- 39.6 days (range, 8-157 days). Antiplatelet therapy was ceased > 3 days prior to CABG in 10/20 patients (50%), but continued until surgery in the remainder. There were no peri-CABG bleeding or neurological complications, but one myocardial infarction occurred (1/20; 5%). Therefore, of the 20 patients who underwent planned carotid stenting followed by CABG, our overall rate of death, stroke, or myocardial infarction was 10%. However, our rate of death, persistent stroke or myocardial infarction was 5%. Planned carotid stenting followed by staged CABG is a viable method of treatment for patients with coexistent carotid and coronary atherosclerosis.

Determining the appropriateness of selected surgical and medical management options in recurrent stroke prevention: A guideline for primary care physicians from the National Stroke Association work group on recurrent stroke prevention

Despite a decade of successful clinical trials for stroke prevention, substantial gaps exist in the application and implementation of this information in community practice. The frequency of guideline use is low, and there remains controversy regarding the standard of practice. Patients with stroke may have multiple risk factors and concomitant stroke mechanisms, factors that are not addressed in stroke clinical trials and guideline statements. New guidelines are needed to account for these complexities and to provide primary care physicians a practical means to achieve stroke prevention. We sought to develop guidelines that can be implemented by primary care physicians to enhance the use of medical and surgical measures for recurrent stroke prevention. We sought to test the applicability of current evidence-based guidelines to daily practice with routine and complex patient case scenarios to determine whether these could be simplified into a more easily applied form for primary care physicians. We used RAND/UCLA Appropriateness Methodology to develop guidelines for the use of interventions supported by randomized controlled trials including carotid revascularization, anticoagulant therapy, antiplatelet therapy, and blood pressure management for the prevention of recurrent stroke. After a systematic literature review of randomized clinical trials we developed a comprehensive list of indications or clinical scenarios to capture decision making. A diverse multidisciplinary panel reviewed and rated each indication according to the RAND Appropriateness Method. First, panelists rated each scenario (1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate) without interaction with other panelists. "Appropriate" was defined as the expected health benefit exceeding its expected negative consequences by a sufficient margin. At a formal interactive session, panelists re-rated all indications. Overall carotid endarterectomy was rated as appropriate when there was 50% to 99% ipsilateral symptomatic carotid artery stenosis, inappropriate with <50% or 100% stenosis (total occlusion), and uncertain when the surgical risk was high. Carotid angioplasty was generally rated as of uncertain value. When there was atrial fibrillation, anticoagulation with warfarin was rated as appropriate when there was a low bleeding risk but of uncertain value when the bleeding risk was high. For patients who were not candidates for warfarin therapy, aspirin, aspirin plus extended-release dipyridamole, or clopidogrel were all rated as appropriate initial therapies. Ticlopidine was considered inappropriate and aspirin plus clopidogrel of uncertain value. With the exception of ticlopidine and aspirin, persons with a prior cerebral ischemic event while on aspirin could receive any of the aforementioned antiplatelet agents or combinations and be considered appropriately treated. The panelists rated a blood pressure of <130/80 mm Hg at 1 year after ischemic stroke as the target level and rated any of the following agents as appropriate initial therapies if there was no diabetes mellitus or proteinuria: diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin-converting enzyme receptor blockers, or combinations of a diuretic and an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Patient risk played a significant role in deterring the panel from recommending certain therapies; however, the presence of atrial fibrillation or large or small cerebral vessel syndromes rarely had significant influence on treatment decisions. Appropriateness was less where bleeding or surgical risk was excessive. Using consensus evidence from clinical trials, we have developed recurrent stroke prevention guidelines for routine and more complex patient scenarios according to appropriateness methodology. Broad application of these guidelines in primary practice promises to reduce the burden of recurrent stroke.